Engage the imagination
Teaching Guidance for 11-14
You can try to use imagination at this point, for example:
Teacher: Imagine we were on a perfectly smooth surface, like a skating rink. One push and the book will carry on moving, sliding but never slowing.
This will be effective if you are a good story teller and the pupils can relate to the experience of an ice skating rink.
However you might also try some experiments with
friction-free skaters. Balloon (hover) buggies, blocks on ball-bearings, dry ice pucks and air-tracks were all introduced to schools in order to demonstrate friction-free motion.
A final task for the imagination is to think about space vehicles in deep space (think Star Trek: Enterprise or Red Dwarf). Such vehicles, once started, will keep moving with no booster rockets blasting away. They just keep on the move, silently and effortlessly. There is no friction force in space to act on them, retarding their motion.